Wikimedia 조직과 Mediawiki 소프트웨어에 대한 조사

1. Wikimedia
Open Collaborative Learning Case Study
KAIST 소프트웨어 대학원
김평화 20113833
2012-03-29
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2. Wikimedia
Contents
• Overview
• Projects
• Features & Figures
• Architectures
• MediaWiki
• References
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3. Wikimedia
Overview
• Wikimedia Foundation
– American non-profit organization, Jimmy Wales
– Several online collaborative wiki projects
⇒ Wikipedia, etc.
– Develop and maintain open content (CC BY-SA)
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4. Wikimedia
Overview
• History
– 2001, Wikipedia
⇒ Perl, Text, UseModeWiki
– 2002~3, Wikipedia Upgrade
⇒ PHP, MySQL, MediaWiki
– 2003, Wikimedia Foundation
– After that, various projects
– 2011, 1 billion people, 50 million articles
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5. Wikimedia
Projects
• Service Projects
– Wikipedia (2001)
– Wiktionary (2002)
– MediaWiki (2003)
– Wikibooks (2003)
– Wikiquote (2003)
– Wikisource (2003)
– Wikimedia Commons (2004)
– Wikispecies (2004)
– Wikinews (2004)
– Wikiversity (2006)
• Internal Projects
– Meta-Wiki (2001)
– Wikimedia Incubator (2006)
– Wikimedia Outreach (2009)
– Wikimedia Strategic Planning (2009)
– Wikimedia Usability Initiative (2009)
– Wikimania
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6. Wikimedia
Features
• Operating the world's fifth
largest web property
• Giving Wikimedia's
volunteers the best possible
tools to do their work
• Developing recruiting
resources for new
volunteers
• Staging outreach and
community events world-
wide
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7. Wikimedia
Features
• Partnering with cultural
institutions
• Working with the
educational sector
• Providing access to
Wikipedia everywhere
• Informing our decision-
making with facts and data
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8. Wikimedia
Figures
• Financials
2011 2011
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9. Wikimedia
Figures
• Page views
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10. Wikimedia
Technical Figures
• 25,000 ~ 60,000 HTTP requests per sec
• 3.5 Gbit per sec of data traffic
• 3 Data centers : Tampa, Amsterdam, Seoul
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11. Wikimedia
Architectures
• LAMP
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12. Wikimedia
Architectures
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13. Wikimedia
CDN (Content Distribution Network)
• 3 clusters on 3 different continents
– Primary cluster in Tampa, Florida
– Secondary caching-only clusters in Amsterdam, the Netherlands and Seoul, South
Korea
• Geographic load balancing (GLB)
– hand out DNS answers based on the estimated location of the querying DNS resolvers
• Squid caching
– Split into two groups : Text and Media
– 75 Squid servers
⇒ up to 40 GB disk, 8 GB memory
– Hit rates : 85% for Text, 98% for Media
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14. Wikimedia
MediaWiki
• MediaWiki
– Free web-based wiki software platform
– All Wikimedia projects run on a MediaWiki platform
– Open source software (GPL v2)
– Release Ver. 1.18.2
• Characteristics in wiki project
– Scales well with multiple CPUs
⇒ Quad-core servers
– One centrally managed
⇒ Hardware shared with external storage
– Simple implementation with LAMP
– Memcached tasks
– Additional extensions
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15. Wikimedia
MediaWiki
• Caching
– Caches everywhere
– Using Memcached
⇒ Open source memory cache software
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16. Wikimedia
MediaWiki
• Persistent Data
– Metadata in core databases
– Actual text in external storages
⇒ All revisions text, Compressed
– Uploaded files in image servers
• Database
– Separate database per wiki
– One master database, many replicated slaves
• Core Database Scaling
– Separating read and write operations
⇒ Read on slaves, write on master
– Separating expensive and cheap operations
– Separating big, popular and small wikis
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17. Wikimedia
MediaWiki
• Core Database Schema
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18. Wikimedia
MediaWiki
• Call Graph Profiling by KCacheGrind
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19. Wikimedia
MediaWiki
• Extensions
– Main extensions (수십가지)
– Third-party extensions (수백가지)
– Major extensions (v.1.17 기준)
⇒ User management
– Nuke, CheckUser, RenameUser
⇒ Communication
– WikiChat, ArticleComments, DPLforum, ContactPage
⇒ Data management
– CategoryTree, View Tree, Semantic MediaWiki
⇒ Interface
– Calendar (Damian) , Inputbox
⇒ Media
– VideoFlash, OggHandler, TimedMediaHandler
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21. Wikimedia
References
• Sunil H. A. North, Deborah M. (2010), Investigating Pedagogical Value of
Wiki Technology
• Mark Bergsma. (2007). Wikimedia Architecture
• http://www.mediawiki.org/wiki/MediaWiki
• http://en.wikipedia.org/wiki/Wikimedia
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